Rajendiran N, Mohandoss T, Saravanan J
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India.
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Nov 11;132:387-96. doi: 10.1016/j.saa.2014.04.123. Epub 2014 Apr 30.
Inclusion complex formation of two local anesthetics drugs (lidocaine (LC) and prilocaine (PC)) with α- and β-cyclodextrins (CDs) in aqueous solution were studied by absorption, fluorescence, time-resolved fluorescence and molecular modeling methods. The formation of inclusion complexes was confirmed by 1H NMR, FTIR, differential scanning calorimetry, SEM, TEM and X-ray diffractometry. Both drugs formed 1:1 inclusion complex and exhibit biexponential decay in water whereas triexponential decay in the CD solution. Nanosized self-aggregated particles of drug: CD complexes were found by TEM. Both experimental and theoretical studies revealed that the phenyl ring with the amide group of the drug is encapsulated in the hydrophobic CD nanocavity. Investigations of energetic and thermodynamic properties confirmed the stability of the inclusion complexes. van der Waals interactions are mainly responsible for enthalpy driven complex formation of LC and PC with CDs.
采用吸收光谱、荧光光谱、时间分辨荧光光谱和分子模拟方法研究了两种局部麻醉药(利多卡因(LC)和丙胺卡因(PC))与α-和β-环糊精(CDs)在水溶液中形成包合物的情况。通过1H NMR、FTIR、差示扫描量热法、扫描电子显微镜、透射电子显微镜和X射线衍射法证实了包合物的形成。两种药物均形成1:1包合物,在水中呈现双指数衰减,而在CD溶液中呈现三指数衰减。通过透射电子显微镜发现了药物:CD复合物的纳米级自聚集颗粒。实验和理论研究均表明,药物中带有酰胺基的苯环被包裹在疏水性的CD纳米腔内。对能量和热力学性质的研究证实了包合物的稳定性。范德华相互作用是LC和PC与CDs形成焓驱动包合物的主要原因。